The NCSRP Board approved the following research projects for funding for fiscal year 2015. Several of the projects are being jointly funded by the United Soybean Board and state checkoff boards.

The areas emphasized for the coming year are soybean diseases, soybean cyst nematode, the soybean aphid, and genetic and biotechnology studies toward the improvement of host resistance and yield. The NCSRP Board is confident that successful completion of the individual projects will significantly advance the understanding of some of the region’s major soybean production problems.

Projects funded for FY 2015 (click on the title for a summary and progress report)

1. Soybean Aphid Management, Resistance and Outreach in the North Central Region

This is a coordinated regional soybean aphid research program on the management of the soybean aphid through classic biological control and host plant resistance.

The project provides for a network of collaborating entomologists, plant breeders, and Extension specialists in twelve states to develop answers to complex issues facing soybean growers in managing the soybean aphid.

Ever since the invasive soybean aphid dramatically changed soybean insect pest management in the North Central Region in the early 2000s, a strong interdisciplinary team of entomologists and plant breeders have worked together to provide pest management research and outreach for the region.The goal of this project is to identify soybean producers' priorities and needs for future research and outreach on insect pest management in the North Central Region.

3. Developing an Integrated Management and Communication Plan for Soybean Sudden Death Syndrome (SDS) in the North-Central Region

The foundational management strategy for SDS is resistant cultivars. However, in some years when environmental conditions are especially favorable for SDS, it's been evident that resistance alone does not provide adequate control. The main goal of this project is to develop crop managment strategies that will ensure that SDS-resistant cultivars will be effective as possible.

This research project will evaluate current and future crop production practices and/or products, how these practices fit into an IPM strategy for SDS and if they enhance the efficacy of SDS-resistant sobyean cultivars.

Planting resistant varieties is the key to managing SDS. Here a comparison of SDS-resistant varieties on either side of a susceptible variety.

4. Breeding to Improve Resistance to SDS in Soybean as a Means to Protect Yield – Delivering Resistant Varieties and Lines

The project draws upon the expertise of a multi-state group of researchers who are collaborating closely to develop varieties and breeding lines with SDS resistance. The goal is to deliver SDS-resistant soybean varieties to farmers, and experimental lines to the seed industry for breeding. Varieties and lines will be developed for maturity groups I to VI.

Up to now, breeders have been mostly working independently, with funds provided by state check-off funds. This has the drawback that promising genetic lines are generally not exchanged among researchers until the time of releasing the new material, often after 8 to 10 years of work. By the close collaboration established in this project, researchers have first-hand knowledge of promising lines early in their development, reducing the time from crossing to the release of public lines.

Some soybean cultivars show good resistance to SDS, however, the inheritance of this resistance is complex because it is controlled by many genes. Improving our understanding of the genetic basis of resistance will help breeders become more efficient in developing new, high-yielding SDS-resistant cultivars.

This project focuses on the genetic basis of SDS resistance. The research spans from fairly basic research on the expression of genes in response to SDS infection to the more applied mapping and confirming of the genetic locations of resistance genes. The SDS resistance genes and marker technology developed in this project will be shared with the other SDS breeding projects and made available to public and commercial breeders.

Rhizoctonia was not able to grow in the top part of the dish which was treated with the bacterial biocontrol agent, compared to the untreated bottom half.

6. Development of a Biological Control Product to Control Sudden Death Syndrome (SDS) and White Mold

In the past few years, several new biological fungicides have been marketed or are in development in private industry that are reported to be effective in controlling SDS and/or white mold. These biological control agents are easy to reproduce and can be applied to soil as a bio-fungicide before planting. They are reported to establish in soil, killing the SDS and white mold fungus, and preventing new infection from occurring. In this study, we are conducting regional field tests in Iowa, Illinois, and Minnesota to test the
effectiveness of these products as well as an experimental biocontrol agent isolated from Iowa soil.

The bio-control activity of a collection of fungal species isolated from soybean production fields will be tested for the potential to improve management of soybean diseases caused by Fusarium spp., Phytophthora sojae, and Pythium spp.

Drought is one of the most important abiotic stresses experienced by soybean plants. Billions of dollars were lost in productivity during the 2012 drought which was one of the most severe since the 1950s. This drought has re-emphasized the need and importance of genetically-improved seed varieties for maintaining seed yield in soybean production. Seedlings that germinated better and emerged from soil, survived the drought conditions relatively well and with lower yield penalties. This observation suggests that improving the germination potential of seeds under mild to moderate stress conditions is a key factor in controlling yield in plants like soybean that flower and seed for a relatively long time.

This research will evaluate the role and signaling mechanisms of novel, plant-specific Gy proteins in seed and pod development and drought/oxidative stress, processes that affect some of the most critical agronomic traits of soybean.

Project objectives

Generate transgenic soybean plants overexpressing group III Gy using tissue-specific promoters and analysis of its effects on overall yield and drought tolerance;

Identify additional effectors of group III Gy family genes by genomics-based approaches for future targeted manipulations.

Soybean field showing symptoms of iron deficiency chlorosis. Photo credit: R.J. Goos, North Dakota State University

9. Iron Deficiency Chlorosis: Getting to the Root of the Problem

Iron deficiency chlorosis (IDC) occurs in the interveinal tissue of young leaves when iron is unavailable to the plant. This is a common problem for soybeans grown on the calcareous soils in the north central states of the US where high pH reduces iron availability to the plant. This availability is further reduced under the wet spring conditions due to the interaction of calcium carbonate with the soil. This results in early season IDC symptoms that are so damaging to yield.

In addition to the soil availability issue, not all varieties have the same ability to metabolize iron because of their different genetic makeup. Efficient plants can reduce the pH near their roots in a manner that releases iron. They also can convert the iron into a state that can be taken up by the root iron transport system and transfer the iron through the root system to the xylem where it binds to a carrier and is transported to leaves. Once it reaches the leaf, it must be unloaded into the cell and form a complex with the key components of the photosynthesis system. It is obvious from this brief summary that multiple genes must function properly to prevent IDC.

The goals of this project is to continue and refine our search for molecular markers and identification of candidate genes associated with iron deficiency (IDC) tolerance in soybean using state-of-the-art genomic technologies. The markers and genes will then be applied to breeding programs in a manner that leads to IDC-tolerant soybean varieties.

Foliar symptoms of Soybean Vein Necrosis Virus, a widespread disease across the Midwest in 2012.

10. Disease Study Group: Focus on New and Emerging Soybean Diseases

Changes in crop production practices and environment impact disease severity and prevalence each year. There are diseases that are an annual threat, such as sudden death syndrome (SDS) and soybean cyst nematode (SCN), but many other diseases are sporadic, new, or emerging in the north-central region.

The North Central Disease Study Group, made up of six core collaborators in five midwestern states and Ontario, Canada, will bridge the gap between research and Extension for emerging disease threats and provide industry and farmers with the most up-to-date information available about emerging diseases each year.

Death of young plant due to charcoal rot infection under extreme heat and drought conditions.
Photo credit: Chris Little, Kansas State University.

11. Improving Awareness and Management of Charcoal Rot in the North-Central Region

Charcoal rot, caused by Macrophomina phaseolina, is a disease of growing importance in the North Central Region; yet current management options are limited. In addition, this disease is more severe when plants are stressed by heat and dry conditions. New fungicide programs and fungicide products are marketed to reduce plant stress, but these products and programs have not been evaluated to determine their impact on charcoal rot development and yield. The goal of this research is to understand under what conditions fungicides may reduce plant stress and yield loss due to charcoal rot so that we may improve our recommendations to farmers interested in using fungicides to mitigate plant stress and/or to manage charcoal rot.

Commercial soybean breeding companies are making major investments in producing new transgenic varieties and commercial soybean breeders are efficient and effective in producing new varieties using the limited genetic diversity available in the commercially used gene pool. However, these companies are doing no research with perennial Glycine and very little research with wild soybean (G. soja) to exploit the important variation in these wild relatives and are dependent on the public sector to make these very important genetic resources available for commercial use.

We have preliminary data that indicate that very useful yield genes exist in both annual (Glycine soja) and perennial (Glycine tomentella) wild relatives of soybean (Glycine max) that are not being used in commercial soybean breeding today.

The USDA Soybean Germplasm Collection contains over 21,000 accessions including wild relatives, landraces, and cultivars from around the world. The majority of unimproved accessions come from China, where soybean was domesticated, as well as Japan and Korea, other areas of ancient cultivation. Domestication resulted in a loss of genetic diversity, with landraces retaining only about 63% of the diversity found in the wild Glycine soja.

Furthermore, 86% of the parentage of US commercial soybean cultivars released between 1947 and 1988 are accounted for by only 17 ancestral Pl accessions. Because it is limited, we need to more effectively use the available diversity in soybean. The goal of this project is to identify and use soybean germplasm with positive alleles for yield and other traits that can be bred into commercial cultivars to effectively increase productivity and expand the genetic base of US soybean varieties. A major challenge in plant breeding is how best to sample a large germplasm collection where phenotypic information for traits such as yield is absent or very limited.

In this project, we are applying new genetic technology and breeding methods to address two bottlenecks in the soybean breeding process. The first bottleneck is the difficulty in effectively selecting new, high yielding varieties early in the breeding process. This is being addressed by testing a new breeding strategy called genomic selection (GS). The second bottleneck is our lack of good information for deciding what combinations of parents should be crossed in a breeding program. To identify solutions for this, simulations will be run to predict the best cross combinations. The GS methods will be developed using information gained from the soybean checkoff sponsored SoyNAM project.

Soilborne diseases caused by various oomycete and fungal pathogens have been a major limitation to soybean production. Phytophthora sojae, Pythium ultimum, Pythium irregulare, and Fusarium graminearum are the major pathogens in the North Central Regions.

Development and planting disease-resistant soybean cultivars remains the most practical, economical, and environmental-friendly solution for eliminating or reducing soybean yield losses from these pathogens. Due to rapid changes of the pathogen, most known resistance genes have become ineffective or partially effective.

The primary goals of this project are to characterize, identify, and/or isolate novel genes/QTLs conferring resistance or partial resistance to P. sojae, P. ultimum,P. irregulare, and F. graminearum, and to deploy the new sources of resistance towards effective disease management in the North Central region.

16. Enhancing Disease Resistance in Soybean Through the Tools of Biotechnology

Our research is contributing to the control of three main soybean viruses, namely bean pod mottle virus (BPMV), soybean mosaic virus (SMV) and alfalfa mosaic virus (AMV), leading to improved yield of soybean seed.

The information gathered from continued field trials will provide more accurate estimates on the yield losses caused by these three viruses, and provide a multi-year assessment of the stability of the resistance phenotype. These data will provide the basis for estimating the potential value of a multi-virus resistance trait in soybean, which is a critical step towards pursuing commercialization of the transgenic traits.

Research objectives:

Determine the long-term agronomic performance and the stability of the resistance phenotype of the transgenic soybean expressing a multi-viral resistance trait

Test the effectiveness of transgenically-expressed small interfering RNAs (siRNAs) and micro RNAs (miRNAs) in conferring resistance to soybean aphid in soybean.

Heterodera glycines, better known as the soybean cyst nematode (SCN), is the most damaging pathogen of soybean in the North Central Region of the USA. This nematode is particularly problematic because viable eggs can persist in the soil for years, making this disease difficult to manage.

A control strategy that would limit SCN egg hatch would be the most effective way to disrupt a critical point in the nematodes’ life cycle. Commonly used nematicides do not kill nematode eggs, but newly discovered SCN viruses reproduce in nematode eggs and lower their viability. The overall goal of this project is to quantify the extent of damage SCN viruses inflict on the nematode in laboratory and field SCN populations, with the hope that these viruses may be deployed as self-replicating SCN-specific biological pesticides in the future.

Soybean cyst nematode (SCN) is currently managed with rotations of non-host crops and the use of SCN resistant soybean cultivars. SCN resistant soybean can be effective, but since SCN is genetically diverse and adaptable, virulent nematodes (SCN that grow and reproduce on a resistant plant) represent a problem. This is also due to the over reliance upon one source of SCN resistance from soybean PI88788.

If virulent SCN accumulation could be monitored in a cost effective way, then the most effective source of SCN resistance could be planted. Currently SCN virulence is measured via the use of the Hg Type test. This greenhouse procedure tests a SCN population for virulence based upon growth on a set of known SCN resistant soybean plants. The Hg Type does work, but since it is a bioassay conducted in a greenhouse it takes one to two months to complete. This project has the aim of developing an inexpensive,quantitative virulence test, based upon the use of nematode virulence genes, that will take only hours to complete.

Previous research has shown that turning off genes by a process known as RNA interference (RNAi) has tremendous potential as a new strategy to increase nematode resistance. This project will investigate the possibility of inserting target gene sequences into the nematodes to obtain durable genetic material lethal to SCN populations.

The researchers will engineer stable transgenic soybean plants with traits that can silence specific nematode genes, evaluate transgenic lines with SCN bioassays to confirm the effectiveness of the level of SCN resistance, and examine the durability of the transgenic traits on single and diverse populations of SCN.

20.
Micronutrients for Soybean Production: A Position Paper for the North-Central Region

Soybean growers in the region are asking many questions concerning possible soybean yield loss due to deficiency of micronutrients. However, there are few extension publications that address micronutrient issues. This is mainly because the available research is very old or funding has limited the scope of recent research at each state. The goal of this new multi-state project is to gather information across key states of the North Central region and prepare a regional position paper on rational use of micronutrients for soybean production.